Part 4 - Berg - Hughes Center

Smackover limestone. The Bossier grades upward into the overlying Terryville
Formation.
Terryville Sandstone
The Terryville, which consists of regressive massive white quartzose sandstones,
extends from Ouachita Parish westward through southern Caddo Parish, Louisiana (Mann
and Thomas, 1964). It was deposited as an offshore sand barrier island that separated the
open sea on the south from a coastal lagoon on the north (Forgotson, 1954; Sloane,
1958). The Terryville attains a maximum thickness of about 1,400 ft (426 m). Only a few
thin, dark gray shale beds occur in this sandstone sequence. The Terryville interval
consists of five sandstone tongues; each of the tongues is composed of one to five
regionally extensive blanket sandstone beds, which are 10 to 50 ft (3-15 m) thick. Oyster
beds occur at the pinch-out edges of some of the sandstones. The Terryville Sandstone
interfingers with and grades northward into the overlying and laterally equivalent Hico
Shale.
Hico Shale
In northern Louisiana, the Hico Shale consists mainly of dark gray shale and a few
thin beds of silty limestone, siltstone, and sandstone. Locally, thin beds of carbonaceous
and pyritic sandstone and shale are present. The dark shales of the Hico are believed to be
a lagoonal facies that accumulated adjacent to the Terryville barrier island (Forgotson,
1954).
Knowles Limestone
The Knowles Limestone in Louisiana, which consists of alternating dark gray,
argillaceous limestone and gray shale, is 300 to 400 ft thick (Mann and Thomas, 1964).
Thin lenses of sandstone occur within, and locally supplant, some of the limestone units.
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